CCS/LAUNCHXL-F28377S: Could you suggest me how to use ADC in LAUNCHXL-F28377S

Hi Kanthanet,

You can find some ADC example SW to get you up and running in ControlSUITE or C2000 ware.  

As far as interfacing to your sensor, that is a pretty broad question.  At a very high level you will want to get the output of your sensor in the range of 0 to VREFHI and you want to drive the ADC with a sufficiently low impedance source such that it can achieve good input settling for your given S+H duration requirements and/or sample rate requirements. 

Dear Gautam,

This is my error as the screenshot below:

and I used this source code:

//###########################################################################
//
// FILE:   adc_soc_epwm_cpu01.c
//
// TITLE:  ADC triggering via epwm for F2837xS.
//
//! \addtogroup cpu01_example_list
//! <h1> ADC ePWM Triggering (adc_soc_epwm)</h1>
//!
//! This example sets up the ePWM to periodically trigger the ADC.
//!
//! After the program runs, the memory will contain:\n
//! - \b AdcaResults \b: A sequence of analog-to-digital conversion samples from
//! pin A0. The time between samples is determined based on the period
//! of the ePWM timer.
//
//###########################################################################
// $TI Release: F2837xS Support Library v200 $
// $Release Date: Tue Jun 21 13:52:16 CDT 2016 $
// $Copyright: Copyright (C) 2014-2016 Texas Instruments Incorporated -
//             http://www.ti.com/ ALL RIGHTS RESERVED $
//###########################################################################

//
// Included Files
//
#include "F28x_Project.h"

//
// Function Prototypes
//
void ConfigureADC(void);
void ConfigureEPWM(void);
void SetupADCEpwm(Uint16 channel);
interrupt void adca1_isr(void);

//
// Defines
//
#define RESULTS_BUFFER_SIZE 256

//
// Globals
//
Uint16 AdcaResults[RESULTS_BUFFER_SIZE];
Uint16 resultsIndex;
volatile Uint16 bufferFull;

void main(void)
{
//
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2837xS_SysCtrl.c file.
//
    InitSysCtrl();

//
// Step 2. Initialize GPIO:
// This example function is found in the F2837xS_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
//
    InitGpio(); // Skipped for this example

//
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
//
    DINT;

//
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the F2837xS_PieCtrl.c file.
//
    InitPieCtrl();

//
// Disable CPU interrupts and clear all CPU interrupt flags:
//
    IER = 0x0000;
    IFR = 0x0000;

//
// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in F2837xS_DefaultIsr.c.
// This function is found in F2837xS_PieVect.c.
//
    InitPieVectTable();

//
// Map ISR functions
//
    EALLOW;
    PieVectTable.ADCA1_INT = &adca1_isr; //function for ADCA interrupt 1
    EDIS;

//
// Configure the ADC and power it up
//
    ConfigureADC();

//
// Configure the ePWM
//
    ConfigureEPWM();

//
// Setup the ADC for ePWM triggered conversions on channel 0
//
    SetupADCEpwm(0);

//
// Enable global Interrupts and higher priority real-time debug events:
//
    IER |= M_INT1; //Enable group 1 interrupts
    EINT;  // Enable Global interrupt INTM
    ERTM;  // Enable Global realtime interrupt DBGM

//
// Initialize results buffer
//
    for(resultsIndex = 0; resultsIndex < RESULTS_BUFFER_SIZE; resultsIndex++)
    {
        AdcaResults[resultsIndex] = 0;
    }
    resultsIndex = 0;
    bufferFull = 0;

//
// enable PIE interrupt
//
    PieCtrlRegs.PIEIER1.bit.INTx1 = 1;

//
// sync ePWM
//
    EALLOW;
    CpuSysRegs.PCLKCR0.bit.TBCLKSYNC = 1;

//
//take conversions indefinitely in loop
//
    do
    {
        //
        //start ePWM
        //
        EPwm1Regs.ETSEL.bit.SOCAEN = 1;  //enable SOCA
        EPwm1Regs.TBCTL.bit.CTRMODE = 0; //unfreeze, and enter up count mode

        //
        //wait while ePWM causes ADC conversions, which then cause interrupts,
        //which fill the results buffer, eventually setting the bufferFull
        //flag
        //
        while(!bufferFull);
        bufferFull = 0; //clear the buffer full flag

        //
        //stop ePWM
        //
        EPwm1Regs.ETSEL.bit.SOCAEN = 0;  //disable SOCA
        EPwm1Regs.TBCTL.bit.CTRMODE = 3; //freeze counter

        //
        //at this point, AdcaResults[] contains a sequence of conversions
        //from the selected channel
        //

        //
        //software breakpoint, hit run again to get updated conversions
        //
        asm("   ESTOP0");
    }while(1);
}

//
// ConfigureADC - Write ADC configurations and power up the ADC for both
//                ADC A and ADC B
//
void ConfigureADC(void)
{
    EALLOW;

    //
    //write configurations
    //
    AdcaRegs.ADCCTL2.bit.PRESCALE = 6; //set ADCCLK divider to /4
    AdcSetMode(ADC_ADCA, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);

    //
    //Set pulse positions to late
    //
    AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1;

    //
    //power up the ADC
    //
    AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1;

    //
    //delay for 1ms to allow ADC time to power up
    //
    DELAY_US(1000);

    EDIS;
}

//
// ConfigureEPWM - Configure EPWM SOC and compare values
//
void ConfigureEPWM(void)
{
    EALLOW;
    // Assumes ePWM clock is already enabled
    EPwm1Regs.ETSEL.bit.SOCAEN    = 0;    // Disable SOC on A group
    EPwm1Regs.ETSEL.bit.SOCASEL    = 4;   // Select SOC on up-count
    EPwm1Regs.ETPS.bit.SOCAPRD = 1;       // Generate pulse on 1st event
    EPwm1Regs.CMPA.bit.CMPA = 0x0800;     // Set compare A value to 2048 counts
    EPwm1Regs.TBPRD = 0x1000;             // Set period to 4096 counts
    EPwm1Regs.TBCTL.bit.CTRMODE = 3;      // freeze counter
    EDIS;
}

//
// SetupADCEpwm - Setup ADC EPWM acquisition window
//
void SetupADCEpwm(Uint16 channel)
{
    Uint16 acqps;

    //
    //determine minimum acquisition window (in SYSCLKS) based on resolution
    //
    if(ADC_RESOLUTION_12BIT == AdcaRegs.ADCCTL2.bit.RESOLUTION)
    {
        acqps = 14; //75ns
    }
    else //resolution is 16-bit
    {
        acqps = 63; //320ns
    }

    //
    //Select the channels to convert and end of conversion flag
    //
    EALLOW;
    AdcaRegs.ADCSOC0CTL.bit.CHSEL = channel;  //SOC0 will convert pin A0
    AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps; //sample window is 100 SYSCLK cycles
    AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 5; //trigger on ePWM1 SOCA/C
    AdcaRegs.ADCINTSEL1N2.bit.INT1SEL = 0; //end of SOC0 will set INT1 flag
    AdcaRegs.ADCINTSEL1N2.bit.INT1E = 1;   //enable INT1 flag
    AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //make sure INT1 flag is cleared
    EDIS;
}

//
// adca1_isr - Read ADC Buffer in ISR
//
interrupt void adca1_isr(void)
{
    AdcaResults[resultsIndex++] = AdcaResultRegs.ADCRESULT0;
    if(RESULTS_BUFFER_SIZE <= resultsIndex)
    {
        resultsIndex = 0;
        bufferFull = 1;
    }

    AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //clear INT1 flag
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}

//
// End of file
//

or I have to set the pin for read ADC?

Now, I can see the value from my current sensor but, 
it has some problem cauesd the value that I got it wasn't the same when I measured by using multimeter like this picture below:

Actually, it should be 2500 and how to change int to float?

Thank you in advance,

kanthanet

-my VREFHI range is 0-5V,
-what is the S+H duration for your sample?
ans. I am not sure how to fing this but, from the datasheet that said "The conversion time is approximately 10.5 ADCCLK
cycles in 12-bit mode and 29.5 ADCCLK cycles in 16-bit mode."
So, my S+H duration is 12 bit (10.5 ADCCLK)
-What is the impedance of your sensor / input source?
ans. I don't know
-What is LSBs?

this is my current sensor datasheet below?

MLX91207-DVK.pdf

Thank you in advance,

kanthanet

I do not think the Launchpad A/D likes negative voltages or voltages above VRefHi.

I've seen 5 Volts to a digital I/O fry a F28069 part.

The values in your adaResultsReg look suspicious. They are all very close to one another.

Here is a snapshot of my board. LaunchXL-F28379D